1. Field of the Invention
The present invention relates to an operator's room for a work machine, and more particularly, to an operator's room situated in the region above the power train in a work machine and being provided with an opening for maintenance which passes through the floor section of the floor frame, and having a lid member for closing the opening installed in the floor section of the floor frame.
2. Description of the Related Art
For example, a tractor, bulldozer, or the like, which is one type of a work machine, comprises a power train, consisting of an engine, or the like, mounted on a main frame equipped with an undercarriage, and is also provided with an operator's room (cab) situated above the power train.
The operator's cab is configured in a skeleton structure formed by assembling a cab frame onto the floor frame, and an opening used for servicing the power train positioned underneath is formed passing through the floor section of the floor frame, this opening usually being closed by a plate (lid member) installed on the floor section.
On the other hand, in the operator's cab of the work machine, such as a bulldozer, or the like, the noise to which the operator (driver) sitting in the cab is exposed, in other words, the noise at the operator's position, tends to be high, due to the infiltration of noise propagated from the power train, which is a noise source, and the like.
Therefore, as means for reducing the noise in the operator's cab, technology has been proposed for suppressing the infiltration of noise into the operator's cab, by adopting a dual structure wherein a sound-proofing wall is provided opposing the partitioning wall that forms the operator's cab, thereby demarcating a sound-proofing space between the partitioning wall and the sound-proofing wall.
Here, by adopting technology for demarcating a sound-proofing space by means of a dual-structured wall, as described above, into the floor section of the floor frame of an operator's cab, it is possible to suppress the noise infiltrating into the operator's cab from the power train positioned below the cab, to a significant degree.
On the other hand, an opening for maintenance purposes as described above is provided in the floor section of the floor frame of the operator's cab, and thus it is necessary to increase sound insulating properties by increasing the thickness of the plate (lid member) that closes off the opening, in such a manner that the infiltration of noise via this plate is suppressed.
However, since the opening in the floor section of the floor frame is formed to a large size from the viewpoint of workability when servicing the power train, and since the plate that closes off this opening is also necessarily formed to a large size, then in order to increase sound insulating properties, the thickness of the material used is increased, and hence the plate becomes large in size and heavy in weight.
Accordingly, the operability when the plate is removed from the floor section of the floor frame, and when the plate is installed on the floor section, is poor, and therefore problems are caused in that the workability of the task of servicing the power train is greatly degraded.
In view of the foregoing, it is an object of the present invention to provide an operator's cab for a work machine whereby a good level of quietness can be achieved, in addition to which good workability in servicing can also be achieved.